idea

Each layout has a AccessorContainer and a ChannelContainer type declaration. The accessor container provides access to channels via pointers and the channel container holds channels.
Each of these classes must provide access to the channels by index and by channel. They also need to implement the common methods: channels(), numberOfChannels() etc.
The accessor container also needs to provide a way of incrementing and decrementing the pointers as well as implementing the requiredChannels method along with the methods for setting the pointers.

Write an Instantiation class that instances either the AccessorContainers or the ChannelContainers. Implement a method called template<ContainerType, LayoutIndex> container() that returns a reference to 
the desired container at the given layout index. 
The Pixel class and a PixelAccessor class are built on the Instantiation class and use the layout information to access the containers. The Pixel class just provides access to the containers channel()
and channelAtIndex method and the PixelAccessor class derives from it and adds the setPointer, increment and decrement methods.